In the asphalt industry, one way of transporting asphalt to the users is in the form of individual packages, which are used often by building contractors as a source of asphalt for roofing and other construction applications. Individual packages of asphalt are often formed at conventional asphalt-processing facilities by pouring molten asphalt into containers made of a metal bottom and paper cylindrical sidewalls. The asphalt is typically poured at temperatures of about 177.degree. C. and the packages are allowed to cool for up to twenty-four hours prior to shipping to users, such as roofing contractors. After removing the paper and metal container, which become waste, the roofing worker places the solid asphalt from the container in a gas-fired melting kettle to melt the asphalt for application. Removal of the paper and metal container is time-consuming and the disposal of the paper and metal container material is burdensome.
Packages have been developed that eliminate the need to remove or dispose of the container. One type of such a package is disclosed in, e.g., U.S. Pat. Nos. 5,452,800 and 5,307,608, which relate to asphalt packages employing thin polypropylene films as the sole containment means and methods for their manufacture.
Another type of consumable asphalt package that has been developed is a moldable container described in International Publication No. WO 96/40838, the disclosure of which is incorporated by reference herein. The consumable containers molded from compositions comprise asphalt and polymer material. The containers may be of cylindrical or rectangular designs, and may be tapered for stacking and include such features as handholds to facilitate handling and annular protrusions or circumferential ribs to enhance dimensional stability.
Although moldable consumable containers have been attained, which have an advantage of reducing fuming in an asphalt-melting kettle, further improvements are desired. More particularly, improvements are sought to facilitate the processing of the containers into asphalt packages as well as the use of the packages.